My Memory Card Needs (Requires) Formatting/Memory Card Says It Needs to Be Formatted

Question: My Memory Card Needs Formatting, Format It or Not?

Case1: My memory card (8GB micro SD card) says that it needs formatting in my Blackberry mobile phone. I can neither listen to music on my Blackberry, nor watching movie. Since all the files are stored to the memory card, it keeps saying memory card needs to be formatted whenever I want to access any data inside the card. Should I format the card so that I can access the data inside? Or is there any other method that I can use to resolve the memory card not formatted error?